1. Field of the Invention
The present invention relates to hypodermic needles used for injecting drugs into parenteral vials and removing the contents after mixing. Air venting of these vials is provided with this apparatus.
2. Description of the Prior Art
Heretofore, small volume parenteral fluid containers have been pierced with hypodermic needles connected to syringes to inject fluid for reconstitution. After reconstitution, the parenteral vial is repunctured and the contents removed. Alternately, a hypodermic needle-syringe combination is left within the vial while it is shaken and then the mixed drug is removed. Unfortunately, in this system the parenteral vial becomes pressurized during the procedure. As a result, a condition can and does occur which is known as "blowback" in which particles of drug are blown into the air. This "blowback" can be very harmful to the personnel preparing such drugs. These hazards are well documented. To overcome these hazards, it is recommended that the reconstituting vial be vented at all times. There are two common procedures used to accomplish this condition. In one procedure, a hypodermic needle is attached to a filter and is pierceably inserted into the parenteral vial. A second needle is attached to a syringe and is used to inject fluid into said vial. After securing the vented needle and syringe-needle combination, the contents are shaken and the reconstituted drug is aspirated into the syringe. The needle-syringe combination is withdrawn from the parenteral vial and is now ready for injection.
In the second procedure, an injection molded piercing pin is used. This piercing pin is approximately 0.2 inches (two tenths of an inch) in diameter and has two lumens or paths in this pin portion. One lumen is preattached to a syringe and the other lumen in the same pin to a vent to which a filter element is attached. U.S. Pat. No. 4,211,588 to RAINES shows such a device. This patent shows a method of making a molding of two pieces and with a spike portion in which separate passageways for air and fluid are provided. The size of the spike of this device prevents its use in some vial systems either because of the stopper size or the occurrence of leakage between the rubber stopper and the spike.
After piercing the parenteral vial with the piercing pin, fluid from the syringe is injected with air escaping through the vent lumen. The contents of the vial are shaken before withdrawal from the vial. After reconstitution (shaking), the drug is aspirated into the syringe through the other lumen. The piercing pin-syringe combination is now withdrawn from the parenteral vial. The fluid path is violated (broken) so as to remove the piercing pin assembly from the syringe and a hypodermic needle is now attached prior to injection.
Drawbacks are present in each of these two procedures. In the first procedure, two needle punctures are required; every time a vial is punctured, there is a risk of contamination. It is evident that the fewer times a container needs to be punctured, the more aseptic the interior. It is also to be noted that this procedure is a very clumsy one as the vial must be shaken while securing two needles and syringe which are attached thereto. This procedure requires much manipulation. In the second procedure, the hole area of the puncturing plastic pin is about twenty times that of a hypodermic needle. The removal of the plastic pin from the wet path and the application of a hypodermic needle to the nose of a wet syringe call for very strict protocols to avoid fluid-path contamination. The large bore resulting from the piercing of the rubber stopper by the molded piercing pin creates large quantities of rubber debris-particulates within the drug which are subsequently aspirated into the syringe and eventually find their way into the patient's circulatory system. The problem in reconstitution is that the mixed medicament be kept sterile during the use of needles and syringes. The syringe conventionally used by attendants is usually disposable and the wrapping insures initial sterility. A U.S. Pat. No. 3,822,909 to OGLE, as issued on May 13, 1975, shows air venting means and commercially produced auxiliary venting needles as in the first procedure are MILLEX-FG (TM of Millipore, Bedford, Mass.): The commercialization of the RAINES patent (U.S. Pat. No. 4,211,588) appears to be by Burron Medical Inc., Bethlehem, Pa., in their Chemo-Dispensing Pin TM. Accordingly, there is a need for a simpler, less cumbersome device which will overcome the problems aforementioned.
Venting apparatus is not new or apparatus that may be converted to include a vent is shown in other issued U.S. patents, among which is U.S. Pat. No. 2,541,272 to MURPHY, as issued Feb. 13, 1951. In this device, the sheath or sleeve, which is closed at its penetrating end, has an air passageway provided by a slot intermediate its extent. Another vent device using two channels is shown in U.S. Pat. No. 3,938,520, as issued to SCISLOWICZ et al, as issued Feb. 17, 1976, which shows a device which cannot be made small for a puncture or penetration of a resilient stopper. A dual flow catheter is shown in U.S. Pat. No. 4,096,860, as issued to McLAUGHLIN on June 27, 1978. This is a Y-block device and there is no suggestion or teaching of a filter in the Y-branch.
Also of note is U.S. Pat. No. 4,294,594, as issued to SLOANE, Jr. et al on Oct. 13, 1981. This is an in-line filter per se and does not pertain to a vented needle. U.S. Pat. No. 4,298,358, as issued to RUSCHKE on Nov. 3, 1981, shows a venting filter but there is no teaching of a combination with a needle. U.S. Pat. No. 4,311,137, issued to GERARD on Jan. 19, 1982, shows a Y-block device where air is filtered and fed to and from the needle channel through a branch portion. This is primarily an infusion device and does not show or teach venting of a mixing container.